Colombia’s invasive hippo problem may have doubled

Biologists were already worried about Colombia’s invasive hippo population. But researchers say the most recent census shows the numbers may be twice as high as they estimated before. The country’s hippos (Hippopotamus amphibius) are descendants of four that drug cartel leader Pablo Escobar illegally imported. After he died in 1993, the hippos escaped from his estate into the wild and reproduced, creating the largest population outside Africa.

A few years ago, researchers estimated 98 hippos in the country. A new study, conducted on foot, by drone and other methods, estimated up to 215.

“This study shows that this is a real issue, and that the state must act urgently,” ecologist Rafael Moreno, who participated in the study, told Nature.

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